As part of the day-long celebration, customers were offered a sneak tasting of the soon-to-be released NextGen Ruby Burger for the discounted price of $3.10, in commemoration of the company's 31 years in business. The new burger boasts a secret sauce and bun.

Doug Cavanaugh, 57, founder and CEO of the company, and Ruby's son, is also introducing a new concept to a number of their restaurant locations – one that will be notable in the company's Costa Mesa location by the end of the year.

"We're starting a new design of the restaurant," Cavanaugh said. "We've been here in the 1940s for 30 years. So now, with the new restaurants, we're going to be moving to brand to a new generation, which is late '50s and early '60s, when I grew up in Los Angeles."

The Next Generation experience will bring a 1960s and classic mid-century modern feel to the existing 17th Street location. Other locations in Southern California also will undergo remodeling in accordance to this new branding concept.

The new brand is inspired by the Googie architecture-inspired coffee shops of Los Angeles in the late sixties. Googie architecture emphasizes geometric patterns, bold angles and Space Age designs.

"The restaurant business and people's tastes have changed more in the last five years than in the previous 20 because of the advent of the Food Network and The Food Channel," Cavanaugh said. "Everybody is a gourmand now; everybody is a foodie. We're going to make the menu a little bit more relevant to the day's taste. So a little more ethnic flavors, artisan-style buns and things like that. We've always had great hamburger buns, but this is new, different."

New menu items, such as the NextGen burger and a kale Caesar salad, will be added to all Ruby's Diner's menus.

"The people are wonderful and you know what, they love Ruby's and that makes me feel good," Ruby said.

Ruby started the day by visiting the first and original Ruby's location on the Balboa Pier in Newport Beach. The location originally opened in 1982. Today, there are 37 Ruby's Diner locations throughout the United States.